Construction element for aircraft



Oct. 21, 1941. c. DORNIER CONSTRUCTION ELEMENT FOR AIRCRAFT Filed Dec. 20, 1953 INVENTOR. CLAUDEDORN/EE.

" M 4 fiw ATTORNEY.

Patented Oct. 21, 1941 UNITED STAT CONSTRUCTION ELEMENT FOR AIRCRAFT Claude Dornier, Friedrichshafen-on-the-Boden see, Germany,'assignor of one-halfto Dornier- Werke G. m. b. 11., Friedrichshafen-on-the- Bodensee, Germany Application December 20, 1938, Serial No. 246,780 In Germany December 23, 1937 4 Claims.

The present invention relates to improvements in construction materials of comparatively great longitudinal extension and which are particularly suitable for the construction of aircraft.

An object of the present invention resides in the provision of a constructional element, having flanges of great resistance against tension or pressure, which is easy to manufacture and of small weight.

An object of the present invention is to provide a constructional element of the type set forth in which the flanges are not solid but are made up of a plurality of plate members which are disposed substantially parallel with respect to one another and between which solid strip members are provided which extend substantially in the longitudinal direction of the element. Said strips are spaced apart from one another and are rigidly connected with said plate members by means of riveting, welding, glueing or the like. Said strip members which act as distance pieces between the plates are of rectangular cross sectional configuration whereby the long sides of the rectangle contact the plates. The rivets, screws, bolts, etc., which serve for interconnecting the strip members and the plates are disposed at such places where a solid cross section is produced by the strip and plates. Where the stress is greater, there may be inserted a particularly wide member so that full cross sections are produced where there is great stress on the flange. The strips may be tapered in their width so as to produce an increasing or decreasing cross section according to the change of the stresses. They may also be tapered in their height or thickness.

Further and other objects of the present invention will be hereinafter set forth in the accompanying specification and shown in the drawing which, by way of illustration, show what I now consider to be a preferred embodiment of my invention.

In the drawing a plurality of embodiments of the present invention are shown:

Figure 1 is a cross sectional View of an I beam according to the present invention.

Figure 2 is a cross sectional view of a girder according to the present invention.

Figure 3 is an isometric showing of a web member as used in the girder shown in Fig. 2.

Figure 4 is a top view of a plurality of distance strips having varying width.

Figure 5 is a longitudinal sectional View of a distance strip member the thickness of which diminishes towards one end of the member,

Figure 6 is a cross sectional view of a box beam according to the present invention.

Referring more particularly to Fig. l of the drawing, I indicates the web to which an upper flange 2 and a lower flange 3 is connected. Web and flanges are interconnected by means of angles 4 riveted to the web as well as individually to the flanges. The upper flange as well as the lower flange is composed of two parallel plates 5 and 6 between which plates distance members I are arranged. Always two adjacent plates and the distance strips therebetween are interconnected by means of rivets 8. In the center of the flange a particularly wide distance strip 9 is provided which is riveted, by means of rivets I 0, to the two angles 4 which connect the web I with the respective flange 2 or 3.

Figure 2 shows a built up girder consisting of web members II one of which is shown individually in Fig. 3 and of an upper flange I2 and a lower flange I3. The web members I I are of U shaped cross sectional configuration having openings [4 and connecting laps I5. Flanges and web members are interconnected by means of the laps I5 and longitudinal angles I6, the latter being riveted individually to the flanges I2 and I3 and the flanges of the web members. Each of the main flanges I2 and I3 consists of two plates I1 and I8 which are disposed parallel to and held at a distance from one another by means of the distance members I 9. When the stresses are particularly great strip members 20 of greater width are used.

The strip members shown in Fig. 4 have great width B at one end and diminish to width b at the other end. Strips of such configuration are used where the stresses on the flanges are different at various parts of their longitudinal extension.

Not only the width but also/or the thickness of the individual strips may be made difierent in accordance with the different stresses acting thereon. A strip member, the thickness H of which at one end is great and diminishes to the thickness h at the other end is shown in Fig. 5.

Figure 6 illustrates a box beam which is composed of two lateral solid webs 2|, an upper flange 22 and a lower flange 23. Each flange consists of three parallel plates 24, 25 and 2B which are held at a distance from one another by means of the distance members 21. The outer distance or strip members 28 are particularly wide in order to facilitate connection with one leg of the angles 29, the other legs of which angles are individually connected with the webs 2|.

While I believe the above described embodiments of my invention to be preferred embodiments, I wish it to be understood that I do not desire to be limited to the exact details of design and construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

l. A longitudinal structural element for air-. craft comprising an upper and a lower flange member, each flange member being built uphof a plurality of longitudinally undivided plate members disposed substantially parallel to one another, longitudinal striplike spacer members individually longitudinally and flatly disposed between and rigidly connected with and separating said plate members and being spaced from one another, and a web member connected to and disposed between and substantially perpendicularly to said flange members.

2. A longitudinal structural element for aircraft as claimed in claim 1 in which said spacer members are of different cross sectional size according to the different stresses they must susta'm.

3. A longitudinal structural element for aircraft as claimed in claim 1 in which said spacer members are of different width according to the different stresses, they must sustain.

14. A longitudinal structural element for aircraft as claimed in claim 1 in which said spacer members are of different thickness according to the different stresses they must sustain.

CLAUDE DORNIER. 

